1. Field of the Invention
The invention relates the attachment of the operative head of an apparatus to a handle for manipulating the head, in particular the head of a cleaning apparatus such as a broom, that has an operative surface contact portion extending laterally of the longitudinal axis of the handle. More specifically, a broom head is made in a T-shape, with an elongated interference fit defined between the handle and the head for a distance adjacent an end of a handle received in a socket, thus distributing along this distance the forces generated during operation of the broom, and withstanding downward force against the broom head without damage or disconnection of the joint between the handle and the broom head.
2. Prior Art
Brooms are well known in the cleaning industry for cleaning in and about the home and commercial and industrial buildings. Brooms characteristically employ a plurality of individual debris-gathering fibers or bristles, connected to a broom head. The bristles are arranged on the head in a band extending laterally from the longitudinal axis of the handle to which the broom head is attached, typically on both sides. Using the handle, a user brushes the bristles over smooth or rough surfaces to gather debris using the fibers, generally working the broom head in a direction perpendicular to its extension lateral of the handle axis.
The handle is elongated, e.g., being about five feet (1.5 m) in length, and is grasped by the user at spaced points along a length above the head. The handle is conventionally attached to the broom head at a perpendicular or angular connection such as a coarsely threaded socket having threads along a short length, normally about one inch (2.5 cm). Alternatively, the handle may be received in a cylindrical bore and held by friction or by a pin passing transversely through the handle and the socket.
Brooms have of course been known for many centuries, the earliest being a bound cylinder of thin twigs that were tied in a bundle to a handle, diverging to define an operative surface at the free ends of the twigs. More sophisticated techniques for connecting a fibers to a handle have come into existence, but it is an aspect of brooms that the surface at which the bristles bear against the cleaning surface extend laterally of the longitudinal axis of the handle. Therefore, a downward pressure on the broom head from the handle, which pressure is greater on one lateral side of the axis than the other, places a stress on the connection of the broom head to the handle.
In operating a broom, downward pressure is frequently exerted unevenly, bearing more strongly on the bristles on one side of the broom than the other. This is particularly true because users do not hold the broom perpendicular to the cleaning surface, instead inclining the handle away from the user's body and thereby inherently placing more pressure on one side than the other. Brooms are often made with uneven bristle lengths to allow the bristles to rest evenly on the cleaning surface when the handle is inclined, and if not the bristles frequently wear unevenly.
The conventional broom head is generally planar, having a wider dimension and a narrower dimension, the narrower dimension being the width of the band of bristles and the wider dimension being the sweeping swath as the broom is typically used. The moment arm acting on the Junction of the handle and the broom head due to uneven pressure on the broom head is greater when the pressure is uneven along the wider dimension, but in normal brushing action, force is exerted to move the broom perpendicular to the wider dimension. Thus, impacts of the broom against obstructions in the sweeping direction also place stress on the handle-broom head joint.
For attaching the bristles in the required pattern, a generally planar broom head has means for attaching the bristles on one side and means for attaching the handle on the other side. The bristles or fibers can be jammed into spaced bores in the broom head, molded into the material of the broom head, attached adhesively, etc. The broom head couples to the handle the forces applied to the bristles when brooming, using a thread, fitting and/or lateral pin as described above.
Brooms having bristles arranged parallel to the longitudinal axis of the handle are one general type, another type being characterized by a push broom. In a push broom, the handle attaches to the broom head at an angle between the handle axis and a line parallel to the bristles. In other respects, similar problems are encountered. A force exerted on the broom head in a manner that is not symmetrical to the axis of the handle, places a stress on the junction between the broom head and the handle. The stress can be substantial in certain situations, such as an impact at a lateral end of the broom head, or even the action of a user placing weight downwardly on the broom head, tending to force the broom head to one side or the other relative to the elongation of the broom head.
The stress on the conventional attachment of a broom handle and broom head i s a substantial shortcoming, and can easily result in the handle being prematurely disengaged from the broom head when a downward, particularly uneven force is applied during brooming operations. Disconnection occurs because the Joint defines a fulcrum at the point of connection between the broom head and broom handle. All the forces applied to the assembled broom by the user are communicated directly to this fulcrum point. Once the forces applied to the connection are greater than the joint can support, the broom head either pulls free or breaks off the end of the broom handle arranged in the joint. At worst, breakage renders the connecting means inoperable for reassembly and use. At best, the joint structures become badly worn and the connection is loosened to the point that subsequent detachment of the broom head is all the more likely to occur.
To better withstand the forces developed between the broom head and the handle without unduly stressing the joint, it is known to add a buttressing cap structure having members extending from the broom head, at points spaced from the handle axis, to a point on the handle that is axially spaced from the joint between the broom head and the end of the handle. The buttressing cap can be placed on top of the broom head. Typically made of a rigid polymer, the cap has sidewalls extending from the broom head to a collar receiving the handle above the basic handle-head joint. The sidewalls and cap define a hollow interior and terminate at an annular top opening (or collar) that is axially spaced a from the open socket on the broom head. The collar and the socket both receive the elongated handle. The collar receives the elongated handle via an interference fit. The socket receives the end of the handle in known manner. The cap has a large bottom opening shaped and configured to fit over the broom head.
The buttressing cap fitted over the broom head provides extra support for the broom construction because forces on the broom head are coupled more along the longitudinal axis of the handle. However, in large part the effect is to define a new and secondary fulcrum at the point of the collar on the handle. Downward brooming forces are distributed at the annular collar or top opening of the cap, relieving some of the force applied force on the direct connection of the handle and broom head at the open socket. However, the cap adds to the complexity and expense of manufacture and assembly because of the additional step of providing another member interposed between the broom head and broom handle. Furthermore, the cap substantially couples lateral force only to the annular top opening of the collar, the interior and bottom opening being hollow and thereby not engaging the handle. As a result, there is a tendency of the handle to bend between the collar and the socket.
It would be desirable to provide a force distributing handle support member to a broom head construction that distributes an applied downward brooming force over the entire length of the support member between an upper buttressing collar and the socket at the broom head and handle basic joint. Further, it would be desirable to integrally form the force distributing handle support member on the broom head. It also would be desirable to have a sufficiently durable support member to maintain the structural integrity and advantageous aspects of a supported broom construction despite continuous downward forces and laterally asymmetrical force applied during regular use. In addition, it would be desirable to optimize the manufacture of supported broom constructions.